HAVANA - The mother of a Jewish US aid contractor jailed in Cuba died on Wednesday, adding to the despondency of a prisoner whose case has strained US-Cuba relations and prompted him to vow not to complete another year of his 15-year term, his lawyer's office said.

US Agency for International Development subcontractor Alan Gross, 65, was convicted for illegally attempting to establish Internet service on the island and ended an 8-day hunger strike in April at the urging of his mother.

Evelyn Gross, 92, died in Plano, Texas, after a long battle with lung cancer, a statement from his lawyers said.

Her death is the latest blow to Gross and is likely to renew supporters' calls for his release.